Any time you drive hard, you should have at least a few kilometers of normal, light-throttle driving as a cool down lap prior to parking.

Obviously, this requires a bit of planning but I think it is a good idea... especially with the turbos.

I would think that with the turbos, if you are just driving normally and you are not in an extremely hot place, you should be able to park the car and let it idle for about 10 seconds prior to shutting it off. I am just speculating though.

From what Fleet says, it seems like BMW has it set up so that you don't have to worry about it too much.

The most important part is to not drive hard before the oil temp has warmed up. Cool down is important too, but only if you've been driving very hard.... Remember, turbos are a wear item. You're only slowing the wear down by taking care of them.

I wet though 2 turbos on my old B5 A4 and am on my second set in the 335. If I keep the 335 long enough I would bet that it will get another set.

you guys scare me, I drive slow 5 minutes before my destination and I let the car idle for 30 sec before i turn it off.

I'm at 65 000 miles.

I'm at that same frame of mind. I've owned more turbo cars than not and wasted a few turbos, however it's always been because I've pushed them past their thresholds of efficiency.

Keep this in mind, "coking" of the center section/bearings is a concern of premature wear on turbos. This is the act of oil disintegrating and leaving carbon deposits on moving parts, therefore causing resistance and unbalance. This is caused by extreme heat and rapid temperature loss. You always battle heat issues with a 2 turbo set up.

Ripping on your car before the oil is up to temp will cause a similar unbalancing effect due to the viscosity of the oil not being there to provide full protection.

As for BMW's failsafe coolant run, I really can't see cycling the coolant after the car shuts off being that super beneficial to saving the turbos. It may help other aspects of the powertrain such as keeping rapid cooling down to a minimum(which is huge when combating warping and stress cracks) but it has very little to do with the major issue with turbo failure. If the oil continued to pump after the car shut off that would be a different story. Watercooled turbos are just designed to keep the center section temps down while running, it's just a heat exchanger. I can't stress enough that oil condition and temp are the winners for this issue.

The only thing I ever did was make sure the oil temp was at least ~170 before going into full boost. Other than that, I got 60,000 miles of 18+ psi, hundreds of drag strip passes and my turbos had no whine and zero shaft play when I took them out.

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The most important part is to not drive hard before the oil temp has warmed up. Cool down is important too, but only if you've been driving very hard.... Remember, turbos are a wear item. You're only slowing the wear down by taking care of them.

I wet though 2 turbos on my old B5 A4 and am on my second set in the 335. If I keep the 335 long enough I would bet that it will get another set.